What I have done to not get the gray colour is:
Fry your button mushrooms in butter, until soft adding a bit of salt and pepper.
make a Béchamelsauce with butter (1 Tablespoon),flour (1 Tablespoon) and milk (1 Cup)
Once your sauce is done, take it off the stove and stir/fold in the mushrooms
Depending on the amount of butter you used for the mushrooms ...

I made my own because of gluten free needs. Made some mistakes because of a few different recipes going at once (added honey instead of maple syrup), and used yellow miso instead of red (because that is what I had) and it turned out just fine. Except for my mistakes, it was super easy. Otherwise, I would buy it.

You don't say how you prepare the sauce, and Alfredo does not contain mushrooms (or flour, or onions). But if you are simply pureeing button mushrooms, then no, there is no way to make it any other color. The mushrooms have black gills, and they will color the whole white sauce.
In theory, you could try removing the gills from button mushrooms before ...

Well, this is what Kikkoman has to say about it:
Kikkoman Less Sodium Soy Sauce is brewed exactly the same way as all-purpose Kikkoman Soy Sauce. However, after the fermentation process is completed, approximately 40% of the salt is removed. Although there is less sodium in Less Sodium Soy Sauce, all the flavor and quality characteristics remain because ...

As passed down from my very Italian Godmother...
Start by browning a few pounds of pork shoulder or other pork as per personal preference.
A good half dozen cloves of garlic, smashed, no need to brown.
A big fist full of parsley. I'm surprised nobody has mentioned parsley. as far as basil or other herbs we never used anything but parsley.
Put everything ...

A typical, basic Italian tomato sauce is made with canned (preferably San Marzano) tomatoes. It is simply made. Saute some onion, with some garlic (not a lot...one or two cloves, sliced, per 28oz can of tomatoes), half a grated carrot (to balance acidity of tomato), some herb (I prefer thyme, but oregano or marjoram are fine). Don't let the onion and ...

Okay so let me first say I'm a novice with Italian food. However I have faced the exact same issue.
Follow these steps that I've created:
Put a teaspoon of dried rosemary in a mug of water and microwave for two minutes. Pour the water into the sauce. Discard or re-dry the rosemary sticks.
Put a tspn of dried oregano straight into the sauce.
A pinch of ...

Teryaki has sugar in it. If you bring it to a boil, the sugar will behave like it typically does in candy-making, and become viscous and possibly tar-like.
You often want this sort of behaviour if you're trying to make a barbeque sauce from meat drippings, but it sounds like you let it boil a little too long.